Picture of striking falcon

The Raptor
Resource Project

P.O. Box 16
Decorah, IA 52101

Bob Anderson

Amy Ries
[email protected]

Picture: Welcome to Falcon Facts!
Home >> Falcon Facts
Picture of falcon 36R at the Sherco power plant
falcon's scientific name is Falco Peregrinus, which means Falcon Wanderer. Three subspecies are recognized in North America: F.P. Pealei from the coastal islands off Alaska; F.P. Tundrius, which nests above the tree line in the Arctic; and F.P. Anatum, which once ranged over North America from coast to coast. In the 1960s, scientists discovered that DDT was interfering in the egg shell formation of meat and fish eating birds. Healthy birds were laying eggs so thin they were crushed by the weight of the incubating adult. By 1965, no Peregrine falcons were fledged in the eastern or Central United States. By 1968, the Peregrine population was completely eradicated east of the Mississippi River. In 1972, use of DDT was severely restricted in the United States and worldwide.

Picture of five eyasses (falcon chicks)BABY FALCONS are called eyasses. They are covered by white down when they are born, which is replaced by feathers in three to five weeks. Although they have a high mortality rate, Peregrines have been known to live as long as 15 years. They usually begin breeding at about two years old. These three young are nesting high atop a power plant stack: power plants have the best production rates in the Midwest.

Picture of two recently banded falcon chicksEYASES ARE helpless. One parent (often the female but sometimes the male) stays with the chicks while the other finds food for the brood. Eyases eat an incredible amount of food - but then, they double their weight in only six days and at three weeks will be ten times birth size. 

Newly hatched chicks are wet and covered with white down. But by three weeks of age, brownish juvenile feathers can be seen poking through the white fuzz. By five or six weeks of age, the white fuzz has been completely replaced by brown feathers. The eyases can be observed jumping around and testing their wings, getting ready to fly. Above: This BirdCam picture of Smoke and Prescott was taken when the young falcons were about 20 days of age.


PEREGRINE FALCONS are about the size and weight of a crow - females are larger and more powerful than males. Adults have slate dark blue-gray wings and backs barred with black, pale undersides, white faces with a black stripe on each cheek, and large, dark eyes. Their wings are long and pointed - Peregrines look, in a nutshell, fast.


have been called nature's finest flying machine. They are nature's fastest fliers: Peregrines have been clocked diving, or stooping, at speeds of up to 220 miles per hour! Peregrine falcons feed primarily on birds they take in the air: their prey includes ducks, pheasants, and pigeons. Some of the power plants that RRP works with have seen the resident pigeon population disappear after Peregrines began nesting on site.

FALCONRY IS an ancient sport. It was practiced in China before the year 2000 BC: falconry is also the subject of some of the oldest Egyptian wall paintings. English playwrite William Shakespeare was a falconry fan who introduced falconry terms into popular speech: the word "Hag" or "Haggard" is the term for a mature wild hawk or falcon. Horus, an Egyptian god, was a Peregrine falcon: the "Eye of Horus" is clearly a stylized Peregrine falcon's eye.
Picture of Mae the falcon feeding one of her chicks
egg, the Peregrine chick has its head tucked under its wing. A large muscle called the hatching muscle runs from the middle of the neck to the top of the head. About 30 days after incubation has started, this muscle contracts. The chick's head snaps up and the egg tooth, a hard pointed knob on top of the beak, cracks the inside of the eggshell. This creates a "pip" - a small hole with tiny cracks spreading out across the shell. One to two days after pipping, the chick begins moving around in the shell. The egg tooth scrapes against the eggshell, cutting a ring through it. 33 days after the egg is laid, the chick breaks out. 

AT ONE time, the type of falcon an Englishman was allowed to own marked his rank. A king, the gyrfalcon; an earl, the peregrine; a yeoman, the goshawk; a priest, the sparrowhawk; and a servant the kestrel. Notable falconers and enthusiasts include Frederick the Second (who wrote what some consider the first book of ornithology), William Shakespeare, Marco Polo, and Ghengis Khan.

Picture of young falcons loosing their baby down
around forty days, young Peregrines begin flying. Peregrine parents encourage flight by "baiting" the young with food, which is no longer neatly prepared and fed directly to the young. It is a lot of fun to watch young Peregrines chasing each other and everything else! As in many other species, Peregrine young learn in part through "playing" - however, this play can be deadly serious when hunting is involved.  Peregrines hunt and eat other birds and are famed for their speed (stooping, or diving, Peregrines have been clocked at speeds of up to 220mph) and aerial prowess.

Here are some bird fact sheets from one of my OTHER favorite web sites, the Animal Diversity Web